I've been using DynamoDB since it was released. In over 3 and 1/2 years of use, this is the first time I've experienced DynamoDB being down.
Don't advertise it if you can't offer it then.
> If you think those nines include software upgrades, you are probably over optimistic.
If you advertise a product with a specific SLA, and you can't meet that SLA, you're a liar. Don't try to blame the victim because of inaccurate/untruthful marketing or engineering.
Not meeting a SLA is not lying.